Safety device for printing-presses



H-, A. W. WOOD.

' SAFETY DEVICE FOR PRINTING PRESSES.

APPLICATION FILED SEPT. 18, 1918.

' Patented May 18, 1920.

2 SHEETS-SHEET 1.

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SAFETY DEVICE FOR PRINTING PRESSES.-

APPLICATION FILED SEPT. 18, I918.

Patented May 18, 1920.

2 SHEETS-SHEET 2- m zfikiai UNITED STATES PATENT OFFICE.

HENRY A. WISE WOOD, OF NEW YORK, N. Y., ASSIGNOR T0 WOOD NEWSPAPERMACHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIR- GINIA.

SAFETY DEVICE FOR PRINTING-PRESSES.

Application filed September 18, 1918.

To all whom it may concern:

Be it known that I, HENRY A. VISE VOOD, a citizen of the United States,residing at New York, in the county of New York and State of New -York,have invented a new and useful Safety Device for Printing-Presses, ofwhich the following is a specification.

This invention relates to a safety device for printing presses, and theprincipal object thereof is to provide means for preventing accident.due to the failure to fix the plate clamps firmly before the press'isstarted, or to their becoming loosened afterward. More specificallystated the invention involves means whereby whenever a "plate cylinderhas a plate clamp in anything but the normal position for firmlyclamping a plate the press will be stopped or the plate cylinderprevented from rotating.

Further objects and advantages of the in-- vention will appearhereinafter.

Reference is to be had to the accompanying drawings, in which Figure 1is an elevation of the end of a plate cylinder with a preferredembodiment of this invention applied thereto and shown in section andthe electrical connections indicated diagrammatically;

Fig. 2 is a similar view showing a modification. and

Fig. 3 is a similar view with the parts in section showing anothermodification.

As is well understood stereotype printing plates are clamped at theirends on plate cylinders of printing presses by clamps which aretightened up by means of screws. Accidents occasionally occur on accountof the fact that theclamps are not securely fastened when the press isstarted or that the screws work loose after having been originallytightened sufficiently. \Vhen this occurs one or more of the plates flyoff the cylinder, pass between the plate and the impression cylinders.or otherwise injure the machine and even sometimes the attendants.

The object of this invention is to prevent these accidents and this iscarried out by placing a safety device in such relation to the clamps atthe end of the plate cylinder that if they are not properly set thepress cannotbe started and furthermore if they work loose after thepress is started it will stop automatically. For-this purpose I takeadvantage of the fact that all newspaper Specification of LettersPatent.

Patented May 18, 1920.

Serial No. 254,550.

presses are now driven by electrical motors which are so arranged thatthe press is put into motion by them at a. slow speed by pressing abutton in a starting circuit. I provide electro mechanical contactsoperating on the feed line or circuit which -con-' trols the runningmotor and cooperating with the plate clamps in such a manner that ifthese clamps are out of position this circuit is opened or closed as maybe necessary so as to prevent the motor from running. This will stop themotor if it is already going or prevent its being started if it is notin operation.

Referring particularly to Fig. 1 of the drawings I have shown theinvention applied to a plate cylinder '10 having plates 11 and clamps 12thereon. These clamps are tightened up by screws 13 working in bosses14.- The ends of these clamps are .located in a plane when the clampsare in normal clamping position.

In the form shown in this figure, I have provided a roller 15 rotatingon an axis axially disposed with respect to the cylinder and adapted tosubstantially contact with the end surface of the two plate clamps 12.The roller freely revolves on. a stud 16 which extends from and is apart of a 1011- gitudinally reciprocating slide 17. This slide movesback and forth on a stud 18 fixed in the frame of the machine which iskept from turning by a set-screw or pin 18. working in a longitudinalgroove 19. A spring-seated pin 20 is supported by and movable with theslide 17, but in the position shown in this figure it is held forward bya strongerflat spring 21 so that when the plates are clamped properlythe roller 15 will just touch the flat end thereof and will rotate onits stud without causing any 'ac-' tion.

The spring 21 forms one end of anelectric circuit 22 operating anelectro-magnet 23. The other end of this circuit terminates in a button24 in position to be engaged by the spring 21 when forced back by theroller 15. due to any irregularity in the setting of the clamps 12 or toany displacement of them from their normal positions. Such displacementor misplacement of either one of the. clamps therefore will moretheslide 17 and the pin 20 back when the cylinder r0 tates part of arevolution so as to cause the spring 21 to engage the contact button 24;

.and close the circuit. This causes the mag net 23 to attract theadjacent end 26 of a lever 27'pivoted at 32 and force the opposite end28 out of contact with the plate 29, thus breaking the main electriccircuit 30 of the high speed or running motor 31. This motor isconnected with'the shaft of thecylin; der 10 and operates it so that ifthe motor is running at the time this action occurs it will stop, andifthe clamp is misplaced in the beginning the motor cannot be started, itbeing understood that the starting button 35 is in the circuit 30 inseries with the contacts 28 and 29. A signal light 33is shown in thecircuit. 30 in series with the contact 24 for the purpose of indicatingthat a clamp is open on that line. It will be understood that there isone of these circuits for each plate cylinder, and therefore the light,preferably a red light, indicates what cylinder clamps need attention.

When the open clamp is closed the flat spring 21 forces the slide 17back into the position shown in Fig. 1, and the circuit 22 is broken.The spring 34 connected with the lever 27 causes the lever to turn onits pivot and close the circuit- 30 at thatpoint so that the motor isready to be started by operation of the usual push button 35. In thisway it will be-seen that the press cannot be started by the usualmeans'when one of the plate clamps on any cylinder ismisplaced in anyway, and that ifone of them becomes loosened when the machine isrunningand gets out of place sufiiciently to release a plate the motorwill be stopped immediately and the attendants will be noti-. fied ofthe particular location of the difficulty so that it can be remedied atonce.

Only a slight modification is shown in Fig. 2 so that detaileddescription will not be necessary. Here the plate clamp is provided witha groove 39 in its circumference in which runs the roller 15. Any slightside motion'of the clamp causes the roller 15 to climb out of thegroove. This necessarily turns the crank 40 with its arm 41 on a pivotstud 42. .This closes acircuit 22 at the contacts 24 and 21.

In the form shown in Fig. 3 the plate clamp 43 is connected with one endof the circuit 22 indirectly through an insulating ring 46 and brush 48.The other end of the circuit is connected to a flat spring 44 in thebottom of the clip screw groove 45 through an insulated ring 47 andbrush 49. On the clamp 43 is a terminal 50'which will engage the spring44 at all timesexcept when the clamp is in properclamping position. Theoperation of. the device is the same as in .the other cases subject tothe modifications above indicated. It will be noted however that in theother cases the cylinder "can in some cases, be rotated apart turn whenone plate clamp is out of position'but in Fig. 3 even this cannot occur.

It will be understood of course that it is usual to provide printingmachines of this character with another. motor which can operate thecylinders independently. This is called the inching system, and is usedin plating up the press. "While plating a man will touch the button ofthe inching system once and the press will move just as far as he wishesto have it move at a very low rate of speed. This enables him to turnthe press over by means of this inching motor into the various positionsnecessary for plating. This motor is entirely independent of the runningmotor 31 and my device is so arranged that while it will prevent thestarting or accomplish the stopping of the running motor it will notinterfere with the inching motor used to propel the press through partsof a revolution during the plating thereof when one or more of theclamps must necessarily be open. The circuit 22 is not connected withthe inching motor, which is not shown in the drawing, so that it doesnot interfere with its operation.

Although I have illustrated and described only three forms of theinvention 1 am aware of the fact that modifications can be made thereinby any person skilled in the art without departing from the scope of theinvention as expressed in the claims. Therefore I do not wish to belimited to allthe details of construction herein shown and described,but what I do claim is 1. The combination'with a printing press having aplate cylinder and plates thereon and its running motor circuit, of astarting and stopping circuit adapted to open the motor circuit andprevent the motor from running, a roll normally running in contact withthe plate clamps, and means whereby when one of the plate clampsis outof normal clamping position it will move said roll out of normalposition and complete the starting and stopping circuit.

2. The combination with a printing press and its plate cylinder andplate clamps, of an electric circuit having means for controlling theoperation of, the press, a slide located at the end of the cylinder andlongitudinally movable, a freely rotatable roller carried by said slideand engaging the ends of the plate clamps, a reciprocable pin mounted onthe slide, a movable-terminal in position to be operated by said pinwhen the slide moves out of position, and a stationary terminal adjacentthereto. said terminals being arranged to open and close said circuit.

In testimony whereof I have hereunto affixed my signature.

HENRY A. WISE 061).

